Improvement in air-engines



R. LORD. AIR ENGINE.

No. 33,303. Patented Sept. 17, 1331.

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UNITED STATES PATENT OFFICE."

RICHARD LORD, or PAWTUCKET, M ssAcHUsn'r'rs.

IMPROVEMENTlN inn-suemes.

Specification forming part of Letters Patent N 0. 33,808, dated September'l'l, 1861.

ings, forming partof this specification, in

which- Eigures I and 2 are vertical sections at right angles to each other of an air-pu mp constructed according to my invention. Fig. 3 is a plan of the same, with the upper valvebox, piston-rods, and connecting-rods in section.

Similar lettersrof reference indicate correspending parts in" the several figures.

The object of my invention is to force air into a reservoir from which it is to be used like steam from a boiler to operate an engine.

The principal feature of my invention consists in a piston composed of a grate upon which a fire is to be lighted, applied to move up and down within a cylinder which is furnished with valves so operated that during sion to force another portion of the air from the same side of the grate into the reservoir.

To enable others to make and use my invention, I will proceed to describe its construction and operation.

'A is the cylinder arranged in a fixed up right position and fitted with two large sliding valves or gates B and .0, the former in its head and the latter in the lower part, as 1 shown in Fig. 2, such valves serving to open communication between the interior of the cylinder and the surrounding atmosphere.

-. To provide for keeping the upper valve cool,

I make the said valve and its casing B hollow and keep up a constant circulation of water througlr them by means of pipes a b. c. The

stems of the valves are connected ,with di fierent arms (1 e of the same rock-shaft 0, by

whose rocking motion both valves are opened or closed simultaneously.

D is a pipe leading from the lower part of the cylinder to the reservoir, (which is not shown,) saidpipe being fitted with a valve which opens automatically when the pressure is greaterin the cylinder than in the reservoir, and closes when the pressure is greater in the reservoir.

E is a small pipe for letting out the pressure from the cylinder while the valves B C are beingopened and so relieving the valves of friction. This pipe, though advantageous, is not indispensable, and if used should be furnished with a valve to be opened at the proper time by some suitable mechanical means.

F is the piston, fitted to work eas'ily within the cylinder and constructed in the form of a grate, with either fixed or movable bars. It is furnished with two rods I I passing through tubes G G, secured to the cylinder-head, and through stuffing-boxes J J at the top of the said tubes, the object of which is to elevate the stuffing-boxes and prevent them from be coming highly heated, the said tubes being-tin communication with the interior of the cylinder, but being out of the circulation of the air and gases which takes place in the cylinder. The two piston-rods I I carry a crosshead K, which is connected by two rods L L with two levers M M, which are secured to a rock-shaft N, fitted to rock in fixed bearings. One of these levers is connected by a rod 1 with a crank Qpn a rotary shaft Q, which may be the crank-shaft of the engine, that is driven bythc air compressed by the pump, or

may be driven by gearing from that shaft or by any other suitable means, and the rotation of the crank Q, acting through the levers M and rock-shaft N, produces a reciprocating movement of the piston F within the cylin der A. The rock-shaft N has applied to it a spiral spring N, to counteract the weight of; The same crankQ' also serves the piston.

to actuate the valves B G, which it does by its connection through a rod T with a rocker R, working on a fixed fulcrum f, the said rocker being also connected by a rod U with a rocking cam S, which is fitted to oscillate upon the shaft Q, the said cam acting alternately upon one and theother of 'two piusg' h, carried by two arms g hen the valve rockshaft 0.

The valves B O and their oporatin g mechanism are so set that they commence opening just before the piston arrives at the bottom of its stroke and are wide open by the time the piston has moved upward a very short distance, and that they commence closing just before the upward stroke of the piston has been completed and are shut; when the piston has descended a very little way. As the piston ascends while the valves B C are open, air rushes in freely through the lower valve C, and the gases of combustion pass out freely through the upper valve B to the atmosphere,'and by this action combustion is supported. As the piston descends with the valves closed, a portion of the cold air which was received below the piston during the upward movement passes through the fire and is heated and expanded along with the gases of combustion, and though this heated air will not at once mix with the cool air below the piston it causes the latter to have the same pressure or tension and forces it out through the pipe D into the reservoir, in which it is obtained at a considerable pressure without a high temperature and but little impregnated by the gases of combustion. The fire is fed through the open valve B,

when necessary, and the ashes are withdrawn from the lower part of the cylinder bya suitable trap.

This apparatus effects the compression of the air without any greater expenditure of mechanical force than is due to the friction of the parts, as the pressure in the cylinder does not resist the movement of the piston, a

and the friction is inconsiderable, for the piston fits the cylinder quite loosely.

What I claim as my invention. and desire to secure by Letters Patent,is

1. The piston constructed as a fire-grate,

applied to the cylinder, in combination with RICHARD LORD. Witnesses:

WM. L. BULLOCK, BENJN. S. FRENCH. 

